Provided is a mechanical seal that eliminates the need to provide an additional bearing, enables size reduction and cost reduction, and can provide stable performance as a bearing. A stationary-side seal ring 20 is disposed on the high-pressure fluid side of a rotating-side seal ring 21, and fixed to a housing 1 and has sliding surfaces 20a, 20c, and 20d supporting a rotating shaft 2 in both a radial direction and a thrust direction. The rotating-side seal ring 21 is axially movably fitted by an urging means 25 fitted on the rotating shaft 2. The rotating shaft 2 has an outer peripheral surface 2a a contacting and sliding on the radial sliding surface 20a of the stationary-side seal ring 20 to be supported radially. Thrust rings 10a and 10b are provided between the stationary-side seal ring 20 and the rotating shaft 2, for supporting the rotating shaft 2 in thrust directions.

An assembly structure of a multi-stage impeller and wheel housing for use in a submersible pump that includes a connecting seat having a drainage channel, shaft, intermediate unit which has a wheel housing, inner guide cover, and impeller. The wheel housing has a central partition plate, with an upper ring housing and lower ring canopy extending upward and downward, respectively, along the perimeter of the central partition plate. The intermediate unit has the upper ring housing connected to the canopy of the connecting seat by a swivel snap structure. A bottom unit has a bottom impeller and bottom wheel housing, which has a water suction port, a bottom plate and a bottom ring housing that extends upward along the perimeter of the bottom plate. A bottom ring canopy of an intermediate unit is connected by a rotating snap structure, and the bottom ring housing is pressed by a sealing ring.

An assembly structure of a multi-stage impeller and wheel housing for use in a submersible pump that includes a connecting seat having a drainage channel, shaft, intermediate unit which has a wheel housing, inner guide cover, and impeller. The wheel housing has a central partition plate, with an upper ring housing and lower ring canopy extending upward and downward, respectively, along the perimeter of the central partition plate. The intermediate unit has the upper ring housing connected to the canopy of the connecting seat by a swivel snap structure. A bottom unit has a bottom impeller and bottom wheel housing, which has a water suction port, a bottom plate and a bottom ring housing that extends upward along the perimeter of the bottom plate. A bottom ring canopy of an intermediate unit is connected by a rotating snap structure, and the bottom ring housing is pressed by a sealing ring.

A modular pinion shaft that includes a tubular member having a first end and a second end, a first pinion gear member secured to the first end by a plurality of fasteners, and a second pinion gear member secured to the first end by a plurality of fasteners. Gear teeth of each of the pinion gear members are aligned by one or more indexing members disposed between the tubular member and each pinion gear member.

A modular pinion shaft that includes a tubular member having a first end and a second end, a first pinion gear member secured to the first end by a plurality of fasteners, and a second pinion gear member secured to the first end by a plurality of fasteners. Gear teeth of each of the pinion gear members are aligned by one or more indexing members disposed between the tubular member and each pinion gear member.

An electric submersible pump (ESP) seal section assembly. The assembly comprises a seal section filled with dielectric oil; a coupling body partially inserted into the seal section, and a coupling body, wherein the coupling body is substantially cylindrical and has a first outside diameter at an upper end of the coupling body, has a second outside diameter smaller than the first diameter below the first outside diameter, has a circumferential tapered shoulder between the portion of the coupling body having the first diameter and the portion of the coupling body having the second diameter; a service-less flange coupled to the seal section, wherein the service-less flange defines a circumferential opening having a circumferential tapered shoulder on an upper edge that contacts the circumferential tapered shoulder of the coupling body.

Devices to couple a drive hub to a driven hub. The devices may comprise a drive hub contoured end connected to a first end of a spacer column and to a spacer drive hub flange. A portion of the drive hub contoured end may project radially out from the spacer column with a first contoured side and a first flat side and may allow movement in an axial direction and transmit torque and an axial load. The devices may comprise a driven hub contoured end connected to a second end of the spacer column and to a spacer driven hub flange. A portion of the driven hub contoured end may project radially out from the spacer column with a second contoured side and a second flat side and may allow movement in an axial direction and transmit torque and an axial load.

Devices to couple a drive hub to a driven hub. The devices may comprise a drive hub contoured end connected to a first end of a spacer column and to a spacer drive hub flange. A portion of the drive hub contoured end may project radially out from the spacer column with a first contoured side and a first flat side and may allow movement in an axial direction and transmit torque and an axial load. The devices may comprise a driven hub contoured end connected to a second end of the spacer column and to a spacer driven hub flange. A portion of the driven hub contoured end may project radially out from the spacer column with a second contoured side and a second flat side and may allow movement in an axial direction and transmit torque and an axial load.

A centrifugal pump assembly includes a pump head, a pump base defining a pump inlet and a pump outlet, a fluid outlet channel from the pump head to the pump outlet, impellers, defining an impeller fluid channel between an impeller inlet and outlet and connected with one of rotor shaft segments including a positive fit coupling for torque transfer between at least two rotor shaft segments, and one or more pump stage housing segments arranged between the pump base and the pump head. The pump stage housing segments have a structure defining a guide passage for receiving pumped fluid from the impeller outlet of the impellers and for guiding pumped fluid to the impeller inlet of another one of the impellers or to the pump head. The pump stage housing segments each have a structure defining at least a part of a wall section of the fluid outlet channel.

An electrical submersible well pump assembly has shaft couplings. One of the couplings has a lower hub that rotates in unison with the motor shaft and an upper hub that rotates in unison with the pump shaft. A helical spring clutch engages both hubs when the motor shaft is being driven by the motor. Ceasing driving rotation of the motor shaft causes the spring clutch to disengage from the upper hub, enabling the pump shaft to rotate the upper hub without rotating the lower hub.